<!DOCTYPE html>
<html lang="en">
  <head>
    <title>tree</title>
    <meta http-equiv="pragma" content="no-cache">
    <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1">
    <meta http-equiv="Cache-Control" content="no-cache, must-revalidate">
    <meta charset="utf-8">
    <script src="./assets/js/d3.min.js"></script>
    <body>
      <div id="button_box">
        <a type="button" id="zoom-in" class="btn btn-default btn-circle zoom-in"><img src="./assets/img/Enlarge.png"></a>
        <a type="button"  id="zoom-out" class="btn btn-default btn-circle zoom-out"><img src="./assets/img/shrink.png"></a>
        <a type="button" class="btn btn-default btn-circle download"><img src="./assets/img/download.png"></a>
        <a type="button" class="btn btn-default btn-circle refresh"><img src="./assets/img/refresh.png"></a>
      </div>
      <div id="load_data">
        <section class="text-center" style="width:150px;height:150;margin-top:50px;position:absolute;top:40%;left:47%;text-align:center">
          <img src="./assets/img/loading.gif">
          <p style="text-align:center">加载数据中...</p>
        </section>
      </div>
  <svg></svg>
  </div>
</body>
</html>